Soldering-flux.



- obtain a mixture to which may be added valid GEORGE l. LUCKEY, OFWILKINSIBURG', PENNSYLVANIA, ASSIGNOR '10 WESTINGHOUSE ELEGTBIC ANDMANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

' sonnnnme-rnux.

Specification of Letters Patent.

Application filed March 1a, 1918. Serial no. 222,107.

Leas es. Xto Drawing.

To all whom it may concern:

Be it known that I, Gnonon P. Luoxnx, a citizen of the United States,and a resident of- Wilkinsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Soldenng-Fluxes, of which the following is a spec fication.

My invention relates to soldering fluxes, and it has for its primaryobject the provision of a soldering flux for use at relatively hightemperatures.- 4 Previous to this,-to the best of my knowledge, there,were no soldering fluxes which could be satisfactorily employed attemperatures between'300 C. and 400 6., and, as a result,'it has beenimpossible to use solders of high melting points, although, in manyinstances, the use of such solders is highly desirable. This is due tothe fact that the ordinary rosin, rosin-zinc chlorid and orgame-materialfluxes cannot be used because the organic material chars attemperatures. between 300 and 400 0., while the boricacid fluxes usedwith brazes melt only at temperaturesthat are too high for use with asolder melting at a temperature under ing point but also with soldersmelting athigher temperatures, up to approximately 400 C Many of themetallic chloride have a cleaning or fiuxing action but their meltingpoints are so high that the solder is oxidized before the flux melts.ever, that, by making a mixture of sodium and potassium chlorids incertain proportion to give a melting'point about that desire andfusing-the mixture together, if

rious metallic chloride to produce a good high-temperature flux of thecharacter do sired. A fused mixture of potassium and sodium chloride, inthe proportions which will give the mixture its lowest melting point,that is in the proportions of substantially 56% potassium chlorid and4e% sodium chlorid, will have a melting point suitable for solderingtemperatures up to 400 C.

l have found, how.

. position. I

Patented net. ii, rare.

Among the metallic chl0rids which may be combined, either singly orseverally, with this fused mixture of sodium and potassium chlorids, arethe-chloride of lithium, cadmium, copper, calcium, zinc, lead and am-'monium, ammonium being considered as a. metal because of its closeanalogy to metals, particularly potassium, in its reactions.

1 have found that a superior soldering flux is formed by combining 65%of zinc chlorid and 10% of a onium chlorid with 25% of the fused mixtureof potassium and sodium chlorids, this latter fused mixture being in theproportions of 56% potassium chlorid and 44% sodium chlorid.

One method which may be followed in making my improved flux consists infusmg a mixture of the proper relative quantities of sodium andpotassium chloride and then adding to the mixture, while melted, theother ingredients desired, such as the zinc and ammonium chlorids,keeping the mixture in a fused state until all of the ingredients havebeen added and thoroughly intermingled by stirring during the addition vof the various materials. When this complete fusing and mixing has beenaccomplished, the flux may bepoured out and cooled. i

This fusing of the flux is an important feature, as the mere mixingtogether of the it is possible, however, that an extremely intimatemixture of the ingredients, such as would be formed by making. anaqueous solution of the various chlorids'employed and then evaporat ngand calcining'the residue,

several ingredients will not produce a flux 3 which W111 fuse at thedesired temperature.

would fuseat such temperatures as would renderit valuable as'a solderingflux. 7

Obviously, my improved soldering flux may be employed in solid form ormay be. dissolved in .water and used as a liquid flux.

Fumhermore, the temperature at which it. v

will melt and run may be regulated by .varying the proportions of -thesodi and employedin its compotamium chloride 7 While the specificproportions and ingre d ents set forth producea very satisfactoryhigh-temperature soldering fli'ux, it is'to. be

understood that I do not impose any limita-' tions upon the manner offog the as;

ioo

not

or the ingredients or proportions of ingredients employed other thanthose set forth of substantially 65% of zinc chlorid and 10% ammoniumchlorid with 25% of a fused mixture of sodiumchlorid.

2. A soldering flux comprising a mixture of substantially 65% zincchlorid and 10% ammonium chlorid with 25% of a fused mixture ofpotassium chlorid and sodium chlorid in the proportion of 56% potassium.

chlorid and 44% sodium chlorid. v

3. A soldering flux including a fused potassium chlorid and mixture ofsodium and otassium chlorids and additional metallic c orid's.

4. A soldering flux including a fused mixture of sodium and potassiumchlorids into which are. fused zinc and ammonium chlorids.

5. A method of forming a soldering flux that comprises fusing a mixtureof sodium and potassium chlorids together and adding metallic chloridswhile the mass is main-' tained in a fused condition.

In testimony whereof, I have hereunto subscribed my name this 19th dayof Feb. 1918.

GEORGE P. LUCKEY.

